The present invention relates to a disk drive unit carrier, disk drive test apparatus, data storage apparatus, a method of testing a plurality of disk drive units, and a method of operating a plurality of disk drive units.
During manufacture of disk drive units, it is necessary to test the disk drive units to ensure that they meet the required specification. As part of the testing operation, it is necessary to control the temperature of the disk drive units. The temperature of the disk drive units is varied across a wide range during testing. In one of the applicant""s own known testing apparatus, the temperature of plural disk drive units is controlled by using cooling or heating air which is common to all of the disk drive units.
It is also desirable to maintain the temperature of a disk drive unit to be within a predetermined range during normal operation of the disk drive unit, i.e. when the disk drive unit is in normal use by an end user. It is common practice in computers to provide a cooling fan which draws in air and causes the cooling air to flow over components within the computer including particularly the CPU, in order to keep down the temperature of the components. However, this provides a crude cooling mechanism and does not provide for separate control of the temperature of the individual components of the computer and particularly the disk drive unit.
According to a first aspect of the present invention, there is provided a disk drive unit carrier for receiving a disk drive unit, the carrier being adapted to carry a single disk drive unit and comprising a temperature control device for controlling the temperature of a disk drive unit received in the carrier to be at a predetermined temperature during operation of the disk drive unit.
The carrier enables the temperature of a disk drive unit in the carrier to be controlled to be at a predetermined temperature during operation of the disk drive unit. It will be understood that, in practice, the temperature will be controlled to be within certain limits of a predetermined temperature and the phrase xe2x80x9cpredetermined temperaturexe2x80x9d shall be construed accordingly. If the disk drive unit carrier is used to receive a disk drive unit during testing of the disk drive unit as part of the manufacturing process, as will be discussed further below the carrier can be located with other similar carriers each carrying their own respective disk drive units. In that case, the present invention allows the temperature of individual disk drive units to be controlled independently. This in turn means that different disk drive units can be at different temperatures at the same time, which is advantageous in that it allows for fully independent testing of the disk drive units including insertion and removal of the disk drive units into respective carriers. Moreover, the various disk drive units can be supplied with power at different levels, which in the prior art apparatus would inevitably mean that the different disk drive units would normally be at different temperatures; in contrast, with carriers of the present invention, the temperatures of disk drive units operating at different power levels can be maintained to be the same if desired.
The temperature control device in a preferred embodiment comprises an air flow control device for causing air to flow across a disk drive unit received in the carrier. As will be discussed further below, the air can be for cooling or warming the disk drive unit and/or for keeping the temperature of the disk drive unit constant.
The carrier may comprise a heat exchanger for selectively receiving and cooling at least a portion of the air that has passed over a disk drive unit received in the carrier thereby to provide chilled air, the air flow control device being selectively operable to cause air to recirculate directly across a disk drive unit received in the carrier, or to cause at least a portion of the air that has passed over a disk drive unit received in the carrier to pass through the heat exchanger to provide chilled air and to cause said chilled air to flow across a disk drive unit received in the carrier, or to cause a mixture of directly recirculated air and chilled air to flow across a disk drive unit received in the carrier.
The air flow control device may be selectively operable to cause air to recirculate across a disk drive unit received in the carrier, or to cause fresh air from outside the carrier to flow across a disk drive unit received in the carrier, or to cause a mixture of recirculated air and fresh air from outside the carrier to flow across a disk drive unit received in the carrier.
Typically, causing air to recirculate across a disk drive unit will cause the temperature of the disk drive unit to rise until heat loss from the carrier matches the power consumption of the disk drive unit. Fresh air will normally be at a temperature which is lower than the temperature of the disk drive unit and thus will tend to cool the disk drive unit. Otherwise, a heat exchanger can be used to provide chilled air. The air flow means can be operated to cause a mixture of recirculated air and fresh or chilled air to flow across the disk drive unit, allowing for intermediate temperatures to be obtained and maintained.
In a preferred embodiment, the air flow control device comprises a baffle which is selectively movable.
A servo control may be provided for controlling movement of the baffle.
The carrier may comprise a selectively operable heater in the air flow path to a disk drive unit received in the carrier for selectively heating air prior to said air flowing across a disk drive unit received in the carrier. This allows the temperature of the disk drive unit to be raised or to be raised more quickly than otherwise.
In one embodiment, the disk drive unit carrier is a disk drive unit test carrier for receiving a disk drive unit during testing of the disk drive unit.
In accordance with a second aspect of the present invention, there is provided disk drive unit test apparatus for receiving a plurality of disk drive units, the test apparatus comprising a plurality of carriers as described above each for receiving a respective disk drive unit to allow the temperature of the respective disk drive units to be independently controlled during testing of the disk drive units.
As mentioned briefly above, such test apparatus allows plural disk drive units to be tested independently of each other as part of the manufacturing process, with independent control of the temperature of each of the disk drive units being possible. This provides a flexibility during testing that has not previously been available.
According to another aspect of the present invention, there is provided data storage apparatus, the apparatus comprising a plurality of carriers as described above each for receiving a respective disk drive unit to allow the temperature of the respective disk drive units to be independently controlled during operation of the disk drive units.
Having independent control of the temperature of plural disk drive units in data storage apparatus provides effectively complete control over the temperature of the individual disk drive units in use in the data storage apparatus. This in turn means that the disk drive units are each likely to be performing within a specified safe temperature range, which makes the performance of the data storage apparatus as a whole more reliable. In contrast, in the prior art where there is only a single temperature control which is common to all of the plural disk drive units, the temperature of an individual disk drive unit can deviate outside the safe temperature range; as well as making that individual disk drive unit less reliable or even likely to fail, this also means that the temperature of the other disk drive units can be affected. These problems are overcome with data storage apparatus according to the present invention.
Each of the apparatus described above may comprise a controller for independent control of the temperature control devices of the disk drive unit carriers.
According to another aspect of the present invention, there is provided a method of testing a plurality of disk drive units, wherein the temperature of each of the disk drive units is independently controlled during testing of the disk drive units.
In a preferred embodiment, the method comprises the step of controlling a flow of air across each of the disk drive units independently thereby to independently control the temperature of each of the disk drive units.
The method may comprise the step of, independently for each disk drive unit, controlling the flow of air across the disk drive unit to cause air to recirculate directly across the disk drive unit, or to cause chilled air obtained by passing at least a portion of the air that has passed over the disk drive unit through a heat exchanger to flow across the disk drive unit, or to cause a mixture of directly recirculating air and chilled air to flow across the disk drive unit.
The method may comprise the step of, independently for each disk drive unit, controlling the flow of air across the disk drive unit to cause air to recirculate across the disk drive unit, or to cause fresh air to flow across the is disk drive unit, or to cause a mixture of recirculated air and fresh air to flow across the disk drive unit.
According to yet another aspect of the present invention, there is provided a method of operating a plurality of disk drive units, wherein the temperature of each of the disk drive units is independently controlled during operation of the disk drive units.
Preferably, the method comprises the step of controlling a flow of air across each of the disk drive units independently thereby to independently control the temperature of each of the disk drive units.
In an embodiment, the method may comprise the step of, independently for each disk drive unit, controlling the flow of air across the disk drive unit to cause air to recirculate directly across the disk drive unit, or to cause chilled air obtained by passing at least a portion of the air that has passed over the disk drive unit through a heat exchanger to flow across the disk drive unit, or to cause a mixture of directly recirculating air and chilled air to flow across the disk drive unit.
In another embodiment, the method comprises the step of, independently for each disk drive unit, controlling the flow of air across the disk drive unit to cause air to recirculate across the disk drive unit, or to cause fresh air to flow across the disk drive unit, or to cause a mixture of recirculated air and fresh air to flow across the disk drive unit.